The subject invention pertains to a method and apparatus for multiplexing in optical fiber communications, for example, as shown and described in U.S. Pat. No. 7,639,909, Method And Apparatus For Spatial Domain Multiplexing In Optical Fiber Communications. As shown therein, multiple light beams, are launched into a single optical fiber, each respective light beam with a corresponding signal. The respective multi-beam excitation and separation in a single optical fiber, as disclosed, is accomplished by launching one or more light beams, each at a different incidence angle and/or input position, into the optical fiber. In this way, each light beam is able to propagate independently according to its own trajectory inside the fiber. As shown and described in U.S. Pat. No. 7,639,909, the projection of the light beam is in an annular ring with a respective radius dependent on the launch angle or skew angle of the light beam into the optical fiber.